1. Field of the Invention
This invention relates to electrical connector of the insulation-piercing type, and more particularly to electrical connectors having contacts which are constructed to receive and electrically contact insulated stranded conductors, as well as insulated solid conductors.
2. Description of the Prior Art
Electrical connectors having insulation-piercing contacts are well known in the art. For example, one may refer to U.S. Pat. Nos. 3,867,005, issued Feb. 18, 1975 to Paul Peter Hoppe, Jr., and assigned to Bunker Ramo Corporation, and to the parent application, Ser. No. 288,988, filed Sept. 14, 1972 concerning electrical connectors and insulation-piercing contacts. Yopp Pat. No. 3,002,176 also discloses this general type of electrical connector, however, without insulation-piercing contacts.
Heretofore, electrical connectors have utilized such techniques as crimping and soldering to connect both solid and stranded conductors to the contacts of an electrical connector.
As set forth in the aforementioned patents, the usual technique for connecting circuit elements, such as the mentioned conductors, to the contacts of the connector, has been to strip the insulation from the end of the conductor and to solder the conductor to a contact. This is a very time consuming operation and the procedure requires considerable skill, particularly where miniaturized connectors are concerned. When using soldering techniques, there is also the possibility of undesirable bridging connections occuring between adjacent contacts of the connector due to the tendency of solder to follow a heated path upon withdrawal of a soldering implement.
As also set forth in the aforementioned patents, an alternative technique which has gained increasing acceptance in the art is the utilization of insulation-piercing terminal elements as a portion of the contacts. Such terminal elements sever or cut through the insulation and establish an electrical connection to the conductor without stripping and without soldering. Insulation-piercing terminal elements usually involve the utilization of a forked structure having cutting edges that sever and penetrate the insulation, and serve as wiping surfaces in some configurations, to make the necessary electrical, and for that matter mechanical, connection with the conductor. The insulation-piercing terminal therefore serves to sever the insulation of the conductor and to act both as a mechanical and electrical connection for the contact and the conductor.
The aforementioned art, which is fully incorporated herein by this reference, is fully acceptable and completely satisfactory for electrically contacting insulated conductors, particularly the solid insulated conductors. When dealing with stranded conductors, however, particularly stranded conductors in the range of 24-28 gauge, oftentimes the strands snag upon, and even become severed by, the edges which are provided for piercing the insulation of an insulated conductor. When using stranded conductors, undesirable problems can therefore arise due to snagging and/or severing of the individual strands including incomplete and sometimes noisy connections which are intolerable.